Try reducing stack trace size during queries

[rmosolgo]

TODO:

• Gather some before benchmarks on memory consumed during runtime (not just limits, but also how much is GC'ed) and stack trace size at certain points
• See if this improves either measure
• The real work is in runtime.rb -- reducing recursive calls and nesting.

[rmosolgo]

New benchmark shows:

Result         Depth
---------------------
Eager          196
Lazy           74
Very Lazy      45

[rmosolgo]

For reference, the "before" profile is here: #3968